摘要： 现有门限代理重签名方案的门限值基本是固定的,但实际应用中需要根据消息的重要程度灵活地变化门限值。为此,基于Suni门限代理重签名方案,提出一种单向可变门限代理重签名方案。在每次进行重签名前,系统会动态设定门限值,每个代理将最初接收的部分子密钥进行重新计算,得到最新门限值下的重签名密钥及其对应的验证公钥,且系统只需提供受托者的公钥信息,避免了受托者承担安全风险。与现有单向可变重签名方案相比,该方案计算效率和安全性更高,签名长度更短。
关键词:
数字签名,
可变门限,
重签名密钥,
门限代理重签名,
单向性
Abstract: In most existing threshold proxy re-signature schemes,threshold value is essentially immutable.However,depending on the significance of re-signature message,the value should be changed dynamically in many practical applications.Based on proxy re-signature scheme Suni,this paper designs a new threshold proxy re-signature scheme which is unidirectional and variable.The system sets the new value of threshold before each re-signature,each agent re-calculates originally received sub-key partially,then each proxy can generate corresponding re-signature sub-key and verification key non-interactively.In order to protect the trustee security and avoid risk,system provides the public key when generating re-
signature key.Compared with other unidirectional and variable re-signature schemes,this scheme can provide better efficiency in computation cost and signature length,and it has high security.
Key words:
digital signature,
variable threshold,
re-signature key,
threshold proxy re-signature,
unidirectionality
中图分类号: